An Introduction to Chemistry Chapter 1Chapter OutlineWhat is a Science?Slide 4ChemistrySlide 61.4 A Scientific Approach to Problem SolvingProblem Solving1.5 The Scientific MethodDefinitionsLaw: Statement of natural phenomena to which no exceptions are known under the given conditions. A law is not an explanation.OutlineSlide 13StepsSlide 15Slide 16Slide 17Slide 181.6 The Particulate Nature of MatterSlide 20Slide 211.7 Physical States of MatterSlide 23Slide 24Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 321.8 Classifying MatterMatter refers to all of the materials that make up the universe.SubstanceHomogeneous MatterHeterogeneous MatterSlide 38PhaseMixtureHomogeneous Mixture (Solution)Slide 42Slide 43Slide 44Slide 45Heterogeneous Mixture of One SubstanceSystemSlide 48Slide 49An Introduction to Chemistry Chapter 1 An Introduction to Chemistry Chapter 1 Hein and Arena Eugene Passer Chemistry Department Bronx Community College© John Wiley and Sons, IncVersion 2.012th EditionChapter Outline1.1 Why Study Chemistry?1.2 The Nature of Chemistry1.3 Thinking Like A Chemist1.4 A Scientific Approach to Problem Solving1.5 The Scientific Method1.6 The Particulate Nature of Matter1.7 The Physical States of Matter1.8 Classifying MatterWhat is a Science?The observation, identification, description, experimental investigation, and theoretical explanation of natural phenomena.Natural Phenomenaexperimentally investigatetheoreticallyexplainobservedescribeidentifyChemistryThe science of the composition, structure, properties and reactions of matter, especially of atomic and molecular systems.Mattercomposition structureproperties reactions1.41.4A Scientific Approach to A Scientific Approach to Problem SolvingProblem Solving1.41.4A Scientific Approach to A Scientific Approach to Problem SolvingProblem SolvingProblem Solving1. Define the problem by recognizing it and stating it clearly. In science this is called an observation .2. Propose solutions to the problem. In science this is called a hypothesis.3. Decide the best way to solve the problem. In science we perform an experiment.1.51.5The Scientific MethodThe Scientific Method1.51.5The Scientific MethodThe Scientific MethodDefinitionsDefinitionsLaw: Statement of natural phenomena to which no exceptions are known under the given conditions. A law is not an explanation.•Hypothesis: A tentative ex planation of certain facts that provide a basis for further experimentation.•Theory: Well-established hypothesis. An explanation of the general principles of certain phenomena with considerable evidence or facts to support it.OutlineOutlineStepsSteps2. Analyze the data to find trends (regularities). 3. Formulate a hypothesis that will account for the data and that can be tested by further experimentation.1. Collect facts or data that are relevant to the problem or question at hand. This is usually done by experimentation.5. Modify the hypothesis to ensure compatibility with the experimental data.4. Plan and do additional experiments to test the hypothesis.P r o v i d e s aB a s i s f o rF u r t h e r E x p e r i m e n t a t i o nT e n t a t i v e E x p l a n a t i o no fC e r t a i n F a c t sH y p o t h e s i sC o n s i d e r a b l e E v i d e n c eo r F a c t sS u p p o r t I tE x p l a n a t i o n o f t h eG e n e r a l P r i n c i p l e so f C e r t a i n P h e n o m e n aT h e o r yEXPLANATIONSS i m p l e S t a t e m e n to f N a t u r a l P h e n o m e n aN o E x c e p t i o n sU n d e r t h e G i v e nC o n d i t i o n sL a w1.61.6The Particulate The Particulate Nature of MatterNature of Matter•Matter can be invisible.Air is matter, but it cannot be seen.•Matter appears to be continuous and unbroken.─Matter is actually discontinuous. It is made up of tiny particles call a toms. •Matter is anything that has mass and occupies space.1.3An apparently empty test tube is submerged, mouth downward in water. Only a small volume of water rises into the tube, which is actually filled with invisible matter–air.1.71.7Physical StatesPhysical Statesof Matterof MatterShape• Definite - does not change. It is independent of its container.Volume• DefiniteParticles•Particles are close together. Theycling rigidly to each other.SOLIDSCompressibility•Very slight–less than liquidsand gases.SolidAmorphous Solid Crystalline SolidParticles lack a regularinternal arrangementParticles exist in regular, repeating three-dimensional geometric patterns.Glass, plastics, gels Diamond, metals, saltsA solid can be either crystalline or a morphous. Which one it is depends on the internal arrangement of the particles that constitute the solid.Shape•Not definite - assumes the shape of its container.Volume• DefiniteParticles•Particles are close together.•Particles are held together by strong attractive forces. They stick firmly but not rigidly to each other.•They can move freely throughout the volume of the liquid.LIQUIDSCompressibility•Very slight–greater than solids,less than gases.GASESShape• No fixed shape.Volume• Indefinite.Particles•Particles are far apart compared to liquids and solids.•Particles move independently of each other.GASESCompressibility•The actual volume of the gas particles is small compared to the volume of space occupied by the gas.–Because of this a gas can be compressed into a very small volume or expanded almost indefinitely.•Attractive forces are strongest in a solid.–These give a solid rigidity.ATTRACTIVE FORCESSolidLiquid•Attractive forces are weaker in liquids than in solids.–They are sufficiently strong so that a liquid has a definite volume.ATTRACTIVE FORCESGas•Attractive forces in a gas are extremely weak.•Particles in the gaseous state have enough energy to overcome the weak attractive forces that hold them together in liquids or solids.–Because of this the gas particles move almost independently of each other.1.81.8Classifying MatterClassifying MatterMatter refers to all of the materials that make up the universe.SubstanceA particular kind of matter that has a fixed composition and distinct properties. Examplesammonia, water, and oxygen.Homogeneous MatterMatter that is uniform in appearance and with uniform properties throughout.Examplesice, soda, pure goldHeterogeneous
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